A Senate proposal, which was originally heralded as a measure of protection for Americans’ e-mail privacy, has been rewritten, giving government agencies more surveillance power than they possess under current law.

According to CNET, Senator Patrick Leahy of Vermont, Democratic chairman of the Senate Judiciary committee, has significantly transformed his original legislation in response to pressure from law enforcement. A vote on the bill, which now allows for warrantless access to Americans’ e-mail, is slated for next week.

The revised bill would provide email access to more than 22 agencies–including the Securities and Exchange Commission and the Federal Communications Commission. These agencies would be able to gain access to Americans’ e-mail, Google Docs files, Facebook wall posts and Twitter direct messages without a search warrant. Also written into the bill is more authority given to the FBI and the Department of Homeland Security (DHS), in certain circumstances. The FBI and DHS would, in these instances, be able to gain full access to Internet accounts without notifying either the owner or a judge.

“Leahy had planned a vote on an earlier version of his bill, designed to update a pair of 1980s-vintage surveillance laws, in late September. But after law enforcement groups including the National District Attorneys’ Association and the National Sheriffs’ Association organizations objected to the legislation and asked him to ‘reconsider acting’ on it, Leahy pushed back the vote and reworked the bill as a package of amendments to be offered next Thursday.”

The reasoning behind the push for the proposed legislation is due to law enforcement concerns that it will impede criminal investigations. Associate Deputy Attorney General, James Baker, has said that requiring a warrant to obtain stored e-mail could have an “adverse impact” on criminal investigations.

Citing how former CIA director David Petraeus’ email was scrutinized by the FBI, Marc Rotenberg, head of the Electronic Privacy Information Center, said that, “even the Department of Justice should concede that there’s a need for more judicial oversight,” not less.

In addition to the FBI and DHS, other agencies that would receive civil subpoena authority for the contents of electronic communications includes: the Federal Reserve, the Federal Trade Commission, the Federal Maritime Commission, the Postal Regulatory Commission, the National Labor Relations Board and the Mine Enforcement Safety and Health Review Commission.

The liberal-conservative-libertarian coalition has expressed deep disapointment in this setback–it was hoped that Congress could be convinced to update the 1986 Electronic Communications Privacy Act to protect documents stored in the cloud.